Original Dolby Digital track or downmix True HD?

[mcarans]

The Blade Runner blu-ray has Dolby True HD and Dolby Digital tracks.

My sound system only copes with Dolby Digital and DTS.

Is is better to play the original Dolby Digital track off the disc or downmix the True HD to DTS (or Dolby Digital) in software?

[crackinhedz]

what receiver do you have? is it connected with an Optical cable?

[hanser]

Originally Posted by mcarans

The Blade Runner blu-ray has Dolby True HD and Dolby Digital tracks.

My sound system only copes with Dolby Digital and DTS.

Is is better to play the original Dolby Digital track off the disc or downmix the True HD to DTS (or Dolby Digital) in software?

I guess that what you mean is using only the stereo tracks of the True HD and using Dolby PrologicII to create surround sound, right? This is at least the alternative you have with older receivers or processors.

Answer: Depends what you want. The Dolby Digital will give you a more precise surround sound with more precise sound location, the True HD may sound fuller and provide more nuances. For Blade Runner I would guess that there is not much of a difference between the both. For a modern action film I would recommend Dolby Digital 5.1, for a Musical or other movie with focus on music (Immortal beloved) True HD in Stereo may be preferred.

[mcarans]

My sound system is connected by optical cable and is old (only capable of Dolby Digital and DTS not any HD formats).

The software blu-ray player can either:
1. output the Dolby Digital 5.1 track off the disc through the optical cable
2. take the Dolby True HD track and trancode it to either DTS 5.1 or Dolby Digital 5.1 and output through the optical cable

Presumably transcoding Dolby True HD to Dolby Digital is pointless, but if DTS has higher bitrate, then maybe Dolby True HD->DTS 5.1 is better than original Dolby Digital track?

[srrndhound]

Originally Posted by mcarans

My sound system is connected by optical cable and is old (only capable of Dolby Digital and DTS not any HD formats).

The software blu-ray player can either:
1. output the Dolby Digital 5.1 track off the disc through the optical cable
2. take the Dolby True HD track and trancode it to either DTS 5.1 or Dolby Digital 5.1 and output through the optical cable

Presumably transcoding Dolby True HD to Dolby Digital is pointless, but if DTS has higher bitrate, then maybe Dolby True HD->DTS 5.1 is better than original Dolby Digital track?

Which BD player do you have? Anyway, using the re-encoding option is not pointless in your case. It is useful if you want to hear the interactive audio features. If you only want to hear the movie soundtrack, you can access the DD or DTS tracks that accompany the respective lossless soundtracks, no need to re-encode in that case.

[srrndhound]

Originally Posted by mcarans

The Blade Runner blu-ray has Dolby True HD and Dolby Digital tracks.

My sound system only copes with Dolby Digital and DTS.

Is is better to play the original Dolby Digital track off the disc or downmix the True HD to DTS (or Dolby Digital) in software?

If the DD track is 640 kbps, it is unlikely there will be any benefit in having the player transcode from PCM/lossless to DTS. You could try listening to them both just for fun and see what you think.

[mcarans]

Thanks for your response. I'll stick to the studio encoded tracks I think.

[gerchy]

Originally Posted by mcarans

The software blu-ray player can either:
2. take the Dolby True HD track and trancode it to either DTS 5.1 or Dolby Digital 5.1 and output through the optical cable

I'm also curious which player can do such things.

[McGarnigal]

it should always just default to a 5.1 you can use

[turboLAZER]

Originally Posted by mcarans

My sound system is connected by optical cable and is old (only capable of Dolby Digital and DTS not any HD formats).

The software blu-ray player can either:
1. output the Dolby Digital 5.1 track off the disc through the optical cable
2. take the Dolby True HD track and trancode it to either DTS 5.1 or Dolby Digital 5.1 and output through the optical cable

Presumably transcoding Dolby True HD to Dolby Digital is pointless, but if DTS has higher bitrate, then maybe Dolby True HD->DTS 5.1 is better than original Dolby Digital track?

Dolby TrueHD cannot be "transcoded" to DTS or Dolby Digital 5.1. If you select the Dolby TrueHD track the player will automatically default to the lossy Dolby Digital 5.1 track to be bitstreamed with the optical connection.

[gerchy]

I assume this does not apply to the DTS-HD audio, because it can only be downmixed to unuseful two channels.

[turboLAZER]

Originally Posted by gerchy

I assume this does not apply to the DTS-HD audio, because it can only be downmixed to unuseful two channels.

when you select a DTS-HD track and you are using an optical or digital coax connection, the 1.5 Mbps lossy DTS core track embedded in the HD track is used. It does not effect the number of surround channels.

[gerchy]

Yes.
Perhaps I expressed myself a little harshly.
I was referring to the mcarans' post that as far as I know no player can't transcode the TrueHD sound to DTS or DTS-HD to Dolby digital.
And in this case downmix to two channels is the only option.

[srrndhound]

Originally Posted by gerchy

Yes.
Perhaps I expressed myself a little harshly.
I was referring to the mcarans' post that as far as I know no player can't transcode the TrueHD sound to DTS or DTS-HD to Dolby digital.
And in this case downmix to two channels is the only option.

I have an Oppo BDP-83 and it converts TrueHD to DTS for S/PDIF when the secondary audio mode is enabled. But yes, it is pointless since either lossless format carries a separate lossy signal for such occasions. Turning off secondary audio, and turning on S/PDIF bitstreaming gets you there.

[gerchy]

Originally Posted by srrndhound

I have an Oppo BDP-83 and it converts TrueHD to DTS for S/PDIF when the secondary audio mode is enabled. But yes, it is pointless since either lossless format carries a separate lossy signal for such occasions. Turning off secondary audio, and turning on S/PDIF bitstreaming gets you there.

You sure?
The BDP-83 user manual contains nothing about that.

By the way ... I saw your great HT system and was curious about the the projected picture when playing DVDs or BR discs. Big difference?

[WiWavelength]

Originally Posted by gerchy

You sure?
The BDP-83 user manual contains nothing about that.

OPPO BDP-83 manual, pg. 58:



AJ

[gerchy]

Interesting - I got the same answer from Oppo service. This is quite an unique feature.
Unfortunately, DTS-HD cannot be converted to DD.

[srrndhound]

Originally Posted by gerchy

By the way ... I saw your great HT system and was curious about the the projected picture when playing DVDs or BR discs. Big difference?

Tnx! I'd say the difference is, well, clear. While DVDs look quite presentable--I was amazed how much more detail popped out when I "upgraded" the Monsters Inc DVD to BD. Texture and detail really come forth.

[Odin75]

As far as I understand it, downmixed TrueHD and regular Dolby Digital are exactly the same thing. All TrueHD tracks have a hidden, independent DD track, that will only become available if you can't play TrueHD. So it won't actually downmix anything, it'll simply switch to the hidden DD track.

TrueHD is different than DTS-HD Master, in that TrueHD have the lossy track separately, while DTS-HD Master has the loosy track in the core. They both have loosy tracks, they don't actually downmix anything.

Of course, that's for blu-rays, as DD in blu-rays is 640kbps, while DD in DVDs is 448kbps.

That's my understanding of it. Feel free to correct me.

[srrndhound]

Originally Posted by Odin75

As far as I understand it, downmixed TrueHD and regular Dolby Digital are exactly the same thing. All TrueHD tracks have a hidden, independent DD track, that will only become available if you can't play TrueHD. So it won't actually downmix anything, it'll simply switch to the hidden DD track.

The OP got off on the wrong foot by asking about downmixing a TrueHD track to DTS. He meant downconversion.

Downmixing means playing a 5.1 track in stereo. And that is an option if you cannot play 5.1 lossless, but want to hear the lossless track in some form. But to hear it, the connection would need to be 2-ch analog or HDMI, as the S/PDIF PCM output is often derived from the lossy "core" even for 2-ch playback. I guess because it's easier.